[Jack Gifford]

Originally Posted by Half-Inch Stud

... a 450cc (22.5 CID) 2-Stroke...

450 cc is a little over 27 c.i.
In any case, this thread is not about HP/c.i. of two-stroke engines.

[455-4+1]

Just replying to HIS question

Its a Honda CBR250F. (just over 15 CID)

4 cylinder 4 stroke with real valve springs
Seems weird setting a shiftlight at 16k to get a shift in before the 18k limiter LOL

Back to topic........................

[Half-Inch Stud]

Originally Posted by Jack Gifford

450 cc is a little over 27 c.i.
In any case, this thread is not about HP/c.i. of two-stroke engines.

Actually, Strong relevance in spinning 9000+ RPM to attain 2X HP for a 4-Stroke engine is;

on par with the 2-Stroke of same CID running at half RPM.

Shows the true cost of >2X HP/CID is (Valvetrain) spin-ability for us Joe 6-packs.

Indicating a dire need to implement a desmodromic valvertain.

If no desmodromic, THEN a NECESSARY begging need to vent the Exhaust through a WINDOW, not a valve. And run a larger Intake valve.

That my friends leads to oiling & bearing technology swaps to avoid crop-dusting along the 1/4 mile.

So, for an attempt at keeping an exhaust window clean and free of traditional oil, i'd like to know if CYL coatings, and accommodating piston skirts eve have a chance to run in an exhaust-windowed block. If not then i want to know if fuel-like lubricants can keep the traditional V8 bearing system survived under Topic loads. If neither can support, then the transition to caged needle bearings on piston pin, rod journal and crank are a development trade for us low-buck enthusiasts.

I hope this serves to summarize the potential developments avenues yet to succeed 1000lb exhaust valvesprings and accommodating valvetrain & block expense. on topic? HIS

Probably worthy of a separate Thread, or forum, so I'll bow-out of this & just read.